My in-laws have a 3-4 acre pond on their property, and it's located in a river bottom and floods occasionally. The pond is well established, it is approx. 30 years old.

There is currently about 4' of water over the pond with some current moving through it right now, it is located in South Louisiana.

My question is, what usually happens to the resident fish in these situations? Do they hunker down and stay in there, or do they tend to move around?

The pond floods every few years and it never seems to really hurt things, but we do notice more Gar and trash fish sometimes, but I assume you get some plusses too, like Shad and things like that.

Also, this pond had a summer oxygen kill 2 years ago, and hasn't flooded since that event. It wasn't a total kill, but a lot of the larger bass were lost. After the kill, I was told that mostly bream, Shad and larger bass were lost, but no crappie or catfish were seen floating. And our rod-and-reel results since the kill seem to indicate the same. Does this sound typical for an oxygen kill?

We have lots of gravel pits here that often get flooded by a river and the fish population changes drastically. One of them is a couple miles from the river and hadn't flooded in decades. It was crystal clear and like looking at an aquarium from a boat. Hoards of bluegill of all sizes and a lot of LMB. I know of at least 2 10pound LMB caught out of it. It flooded a few years ago when a dam broke and is completely different now. Very few BG and a rare small LMB. Lots of carp, bowfin, and gar. People also catch a few BH and CC now.

I can't answer your question, but will offer an observation that is along the subject line and would be interested if my observation sounds logical to the experts.

My observation has to do with the fish movement between three of my ponds that have short term flooding between them during large rain events.

It appears to me nature gives the urge to the tiny fish to swim upstream, even in extremely shallow water. Maybe natures way of populating new bodies of water and a way for new small fish to find new homes?

When I dug my pre-sediment pond (which is very small) and it was dry, after the first significant rain which filled it and overflowed into the bigger sediment pond, numerous 2" BG were found. I had only stocked FHM in it (before it reached full pool), yet there were these small BG even though the water got no deeper than an inch or two during the overflow. The BG apparently swam upstream against the current in this very shallow water to get into this pre-sediment pond.

It surprised me there were so many and the small pond (about 20x40') populated so quickly.

We have lots of gravel pits here that often get flooded by a river and the fish population changes drastically. One of them is a couple miles from the river and hadn't flooded in decades. It was crystal clear and like looking at an aquarium from a boat. Hoards of bluegill of all sizes and a lot of LMB. I know of at least 2 10pound LMB caught out of it. It flooded a few years ago when a dam broke and is completely different now. Very few BG and a rare small LMB. Lots of carp, bowfin, and gar. People also catch a few BH and CC now.

Interesting point about the water color. The first time I personally saw this particular pond flood was about 7-8 years ago, and it definitely lowered the viz from about 2 feet to less than 1 foot, and it stayed that way. Also, they seem to get dark brown algae blooms in the summer since then as well, which is probably a big part of the summer fish kill 2 years ago, although I wasn't down there at the time that happened so I'm guessing.

I didn't mention it before, but this pond has a constant supply of underground water from a pipe at the upper end- I understand that this water isn't oxygenated, but it is clear.

We have lots of gravel pits here that often get flooded by a river and the fish population changes drastically. One of them is a couple miles from the river and hadn't flooded in decades. It was crystal clear and like looking at an aquarium from a boat. Hoards of bluegill of all sizes and a lot of LMB. I know of at least 2 10pound LMB caught out of it. It flooded a few years ago when a dam broke and is completely different now. Very few BG and a rare small LMB. Lots of carp, bowfin, and gar. People also catch a few BH and CC now.

Interesting point about the water color. The first time I personally saw this particular pond flood was about 7-8 years ago, and it definitely lowered the viz from about 2 feet to less than 1 foot, and it stayed that way. Also, they seem to get dark brown algae blooms in the summer since then as well, which is probably a big part of the summer fish kill 2 years ago, although I wasn't down there at the time that happened so I'm guessing.

I didn't mention it before, but this pond has a constant supply of underground water from a pipe at the upper end- I understand that this water isn't oxygenated, but it is clear.

Personally, I think there is a lot to be said about BOW's that get flooded on occasion. They are not so good if you are wanting just certain species and trying to manage for them but they are great fishing holes. There's just something about getting a tug on your line and having no idea what is on the other end.

When my pond was completed, that night we had a weather system stall on top of our part of the world and dump 7"+ rain on us. Between the nearby creek and the huge aggressive watershed that I have, my place filled up literally overnight to the point of breaching the dam. I began to stock the pond 2 weeks later with forage fish (FHM, CNBG, RES...). This was August 2014. It was not until the spring/summer of 2015 that I started catching different species of fish that I had never stocked. They had also spawned either the summer before and / or that spring. I believe fish caught up in massive drainage situations have no choice but to go with the flow of water. My water came from up north of me and I know of several ponds up north of me (looking at google earth). Since then, the creek has been re-dug and re-routed so hopefully, I will not have any more issues like that reoccur.

I do have a nephew in SW Louisiana that has a 4 1/2 acre pond on 45 acres in a flood zone. He indicated that the bigger fish (LMB) appear to stay put during flooded times, but as mentioned above, he gets his fair share of choupique (bowfin), gar, and an occasional alligator that make it in to his place. I guess it would be depend on the situation, the geographics, amount of water, and the avenue of water coming through.

Well, the water went down and my FIL found a 3lb bass that had gotten stuck on dry land and died, but most of the area downstream from the pond is wooded so there's no telling how many others wound up down there.

This was the highest water with the most current that they have ever had according to him.